A prospective single blind trial in 50 patients was performed to investigate the effect of posture on post lumbar puncture headache (LPH). A difference between the frequency of headache at five hours between the two groups (prone for four hours, versus 30 degrees head down tilt for 30 minutes followed by supine posture for 3 1/2 hours) did not reach significance. These findings do not support the suggestion that a prone posture, by possibly reducing cerebrospinal fluid (CSF) leakage, significantly reduces the frequency of this common clinical problem. The value of bed rest after lumbar puncture remains equivocal. Other methods used for reducing LPH are reviewed.